Made GraphSON 3.0 the default config in GraphSONMapper

This change should have been made back when we moved 3.0 to the default earlier with Gremlin Server. CTR
diff --git a/CHANGELOG.asciidoc b/CHANGELOG.asciidoc
index e3df862..1d6e808 100644
--- a/CHANGELOG.asciidoc
+++ b/CHANGELOG.asciidoc
@@ -42,6 +42,7 @@
 * Refactored `Traversal` semantics to always expect `EmptyStep` as a parent if it is meant to be the root `Traversal`.
 * Configured GraphBinary as the default binary serialization format for the Java Driver.
 * Configured GraphSON 3.0 as the default text serialization format when no serializer can be determined.
+* Configured GraphSON 3.0 as the default setting for the `GraphSONMapper`.
 * Bump to Neo4j 3.4.11.
 * Added a parameterized `TypeTranslator` for use with `GroovyTranslator` that should produce more cache hits.
 * Added support for `TextP` in Neo4j using its string search functions.
diff --git a/gremlin-core/src/main/java/org/apache/tinkerpop/gremlin/structure/io/graphson/GraphSONMapper.java b/gremlin-core/src/main/java/org/apache/tinkerpop/gremlin/structure/io/graphson/GraphSONMapper.java
index 30112f9..bfa239b 100644
--- a/gremlin-core/src/main/java/org/apache/tinkerpop/gremlin/structure/io/graphson/GraphSONMapper.java
+++ b/gremlin-core/src/main/java/org/apache/tinkerpop/gremlin/structure/io/graphson/GraphSONMapper.java
@@ -198,7 +198,7 @@
         private boolean loadCustomModules = false;
         private boolean normalize = false;
         private List<IoRegistry> registries = new ArrayList<>();
-        private GraphSONVersion version = GraphSONVersion.V2_0;
+        private GraphSONVersion version = GraphSONVersion.V3_0;
 
         /**
          * GraphSON 2.0/3.0 should have types activated by default (3.0 does not have a typeless option), and 1.0
@@ -219,7 +219,7 @@
         }
 
         /**
-         * Set the version of GraphSON to use. The default is {@link GraphSONVersion#V2_0}.
+         * Set the version of GraphSON to use. The default is {@link GraphSONVersion#V3_0}.
          */
         public Builder version(final GraphSONVersion version) {
             this.version = version;
diff --git a/gremlin-core/src/main/java/org/apache/tinkerpop/gremlin/structure/io/graphson/LegacyGraphSONReader.java b/gremlin-core/src/main/java/org/apache/tinkerpop/gremlin/structure/io/graphson/LegacyGraphSONReader.java
index 3125e73..7432e22 100644
--- a/gremlin-core/src/main/java/org/apache/tinkerpop/gremlin/structure/io/graphson/LegacyGraphSONReader.java
+++ b/gremlin-core/src/main/java/org/apache/tinkerpop/gremlin/structure/io/graphson/LegacyGraphSONReader.java
@@ -205,7 +205,6 @@
         private boolean loadCustomModules = false;
         private List<SimpleModule> customModules = new ArrayList<>();
         private long batchSize = 10000;
-        private boolean embedTypes = false;
 
         private Builder() {
         }
@@ -236,9 +235,12 @@
         }
 
         public LegacyGraphSONReader create() {
-            final GraphSONMapper.Builder builder = GraphSONMapper.build();
+            // not sure why there is specific need for V2 here with "no types" as we don't even need TP3 GraphSON
+            // at all. Seems like a standard Jackson ObjectMapper would have worked fine, but rather than change
+            // this ancient class at this stage we'll just stick to what is there.
+            final GraphSONMapper.Builder builder = GraphSONMapper.build().version(GraphSONVersion.V2_0);
             customModules.forEach(builder::addCustomModule);
-            final GraphSONMapper mapper = builder.typeInfo(embedTypes ? TypeInfo.PARTIAL_TYPES : TypeInfo.NO_TYPES)
+            final GraphSONMapper mapper = builder.typeInfo(TypeInfo.NO_TYPES)
                     .loadCustomModules(loadCustomModules).create();
             return new LegacyGraphSONReader(mapper.createMapper(), batchSize);
         }